KSessionSelector.java

/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.kie.workbench.common.widgets.client.widget;

import java.util.ArrayList;
import java.util.List;
import javax.inject.Inject;

import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.ui.IsWidget;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwt.view.client.SelectionChangeEvent;
import org.jboss.errai.common.client.api.Caller;
import org.jboss.errai.common.client.api.RemoteCallback;
import org.jboss.errai.common.client.ui.ElementWrapperWidget;
import org.kie.workbench.common.services.shared.kmodule.KBaseModel;
import org.kie.workbench.common.services.shared.kmodule.KModuleModel;
import org.kie.workbench.common.services.shared.kmodule.KModuleService;
import org.kie.workbench.common.services.shared.kmodule.KSessionModel;
import org.kie.workbench.common.services.shared.project.KieProject;
import org.kie.workbench.common.services.shared.project.KieProjectService;
import org.uberfire.backend.vfs.Path;
import org.uberfire.commons.validation.PortablePreconditions;
import org.uberfire.mvp.Command;

public class KSessionSelector
        implements IsWidget {

    private static String DEFAULT_KIE_BASE = "defaultKieBase";
    private static String DEFAULT_KIE_SESSION = "defaultKieSession";
    private static String NON_EXISTING_KBASE = "---";

    private KSessionSelectorView view;
    private Caller<KieProjectService> projectService;

    private Caller<KModuleService> kModuleService;
    private KModuleModel kmodule;

    private Command selectionHandler;

    @Inject
    public KSessionSelector(final KSessionSelectorView view,
                            final Caller<KieProjectService> projectService,
                            final Caller<KModuleService> kModuleService) {
        this.view = view;
        this.projectService = projectService;
        this.kModuleService = kModuleService;

        view.setPresenter(this);
    }

    public void init(final Path path,
                     final String ksession) {
        projectService.call(getSuccessfulResolveProjectCallback(ksession)).resolveProject(path);
    }

    private RemoteCallback<KieProject> getSuccessfulResolveProjectCallback(final String currentKSession) {
        return new RemoteCallback<KieProject>() {
            @Override
            public void callback(KieProject project) {
                kModuleService.call(getSuccessfulLoadKModuleCallback(currentKSession)).load(project.getKModuleXMLPath());
            }
        };
    }

    private RemoteCallback<KModuleModel> getSuccessfulLoadKModuleCallback(final String currentKSession) {
        return new RemoteCallback<KModuleModel>() {
            @Override
            public void callback(KModuleModel kmodule) {
                KSessionSelector.this.kmodule = kmodule;

                initKBases(currentKSession);
                selectCurrentKBaseAndKSession(currentKSession);
            }
        };
    }

    private void selectCurrentKBaseAndKSession(final String currentKSession) {
        if (isNotNullOrEmpty(currentKSession) && kmoduleContainsCurrentKSession(currentKSession)) {
            selectFromModel(currentKSession);
        } else {
            selectFirstKBaseAndKSession();
        }
    }

    private void initKBases(final String currentKSession) {
        view.clear();

        if (kmodule.getKBases().isEmpty()) {
            addMockKBaseModel(DEFAULT_KIE_BASE,
                              DEFAULT_KIE_SESSION);
            view.addKBase(DEFAULT_KIE_BASE);
        } else {
            for (KBaseModel kBase : kmodule.getKBases().values()) {
                view.addKBase(kBase.getName());
            }
        }
        if (isNotNullOrEmpty(currentKSession) && !kmoduleContainsCurrentKSession(currentKSession)) {
            addMockKBaseModel(NON_EXISTING_KBASE,
                              currentKSession);
            view.addKBase(NON_EXISTING_KBASE);
            view.showWarningSelectedKSessionDoesNotExist();
        }
    }

    private void addMockKBaseModel(final String kbaseName,
                                   final String ksessionsName) {
        KBaseModel kbaseModel = new KBaseModel();
        kbaseModel.setName(kbaseName);
        KSessionModel ksessionModel = new KSessionModel();
        ksessionModel.setName(ksessionsName);
        kbaseModel.getKSessions().add(ksessionModel);
        kmodule.getKBases().put(kbaseName,
                                kbaseModel);
    }

    private boolean isNotNullOrEmpty(final String ksession) {
        return ksession != null && !ksession.trim().isEmpty();
    }

    private boolean kmoduleContainsCurrentKSession(final String currentKSession) {
        if (isNotNullOrEmpty(currentKSession)) {
            for (KBaseModel kbase : kmodule.getKBases().values()) {
                for (KSessionModel ksession : kbase.getKSessions()) {
                    if (ksession.getName().equals(currentKSession)) {
                        return true;
                    }
                }
            }
        }

        return false;
    }

    public void onKBaseSelected(final String kbaseName) {
        final List<KSessionModel> ksessions = kmodule.getKBases().get(kbaseName).getKSessions();
        listKSessions(ksessions);

        view.setSelected(kbaseName,
                         ksessions.iterator().next().getName());
    }

    public String getSelectedKSessionName() {
        return view.getSelectedKSessionName();
    }

    private void selectFromModel(final String currentKSession) {
        for (KBaseModel kbase : kmodule.getKBases().values()) {
            for (KSessionModel ksession : kbase.getKSessions()) {
                if (ksession.getName().equals(currentKSession)) {
                    listKSessions(kmodule.getKBases().get(kbase.getName()).getKSessions());
                    view.setSelected(kbase.getName(),
                                     currentKSession);
                    break;
                }
            }
        }
    }

    private void selectFirstKBaseAndKSession() {

        KBaseModel firstKBase = kmodule.getKBases().values().iterator().next();

        List<KSessionModel> ksessions = firstKBase.getKSessions();

        listKSessions(ksessions);

        view.setSelected(firstKBase.getName(),
                         ksessions.iterator().next().getName());
    }

    private void listKSessions(List<KSessionModel> ksessions) {
        List<String> ksessionNames = new ArrayList<String>();
        for (KSessionModel ksession : ksessions) {
            ksessionNames.add(ksession.getName());
        }
        view.setKSessions(ksessionNames);
    }

    @Override
    public Widget asWidget() {
        return ElementWrapperWidget.getWidget(view.getElement());
    }

    public void onSelectionChange() {
        if ( selectionHandler != null ) {
            selectionHandler.execute();
        }
    }

    public void setSelectionChangeHandler(final Command handler) {
        this.selectionHandler = PortablePreconditions.checkNotNull("handler", handler);
    }
}